ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Organic Chemistry  (9)
  • Dynamic gas chromatography
  • Cyclodextrins
  • 1980-1984  (9)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1982 (1982), S. 1615-1622 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of the N-Terminal Amino Acid of the Nikkomycins I, J, X, and ZA mixture of four stereoisomers of 2-amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbutanoic acid (14), the N-terminal amino acid of the nikkomycin antibiotics could be synthesized in a twelve-step procedure. By comparison of 1H NMR spectra, mass spectra and of the gas chromato-graphic behaviour of various derivatives the constitution and relative configuration of the natural compound has been confirmed.
    Notes: Ein Gemisch aus vier Stereoisomeren von 2-Amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbuttersäure (14) der N-terminalen Aminosäure der Nikkomycin-Antibiotika konnte in einer zwölfstufigen Synthese dargestellt werden. Durch Vergleich der 1H-NMR-Spektren, Massenspektren und des gaschromatographischen Verhaltens verschiedener Derivate von Synthese- und Naturprodukt wird die Richtigkeit der angenommenen Konstitution und relativen Konfiguration bestätigt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Configuration of 2-Amino-4-hydroxy-4-(5-hydroxy-2-pyridyl)-3-methylbutyric Acid, the N-Terminal Amino Acid of the NikkomycinsThe N-ethylthio(thiocarbonyl)derivative 2 of the N-terminal amino acid 1 of the nikkomycin antibiotics shows a positive Cotton effect in its circular dichroism spectrum and therefore 1 is assigned to the L-series. The relative configuration of the C atoms 3 and 4 was ascertained by 1H-NMR investigations and crystal structure analysis. Accordingly, 1 is assigned the configuration 2S,3S,4S.
    Notes: Das N-Ethylthio(thiocarbonyl)derivat 2 der N-terminalen Aminosäure 1 der Nikkomycin-Antibiotika weist Circulardichroismus mit positivem Cottoneffekt auf und 1 ist daher der L-Reihe zu-zuordnen. Die relative Konfiguration an den C-Atomen 3 und 4 wurde durch 1H-NMR- und Kristallstrukturuntersuchungen bestimmt. Danach hat 1 die Konfiguration 2S,3S,4S.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1606-1609 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Amino Acids and Peptides, IV. - Synthesis of Furan Derivatives from N-Methyl Amino AcidsIn the reaction of N-methyl homophenylalanine and N-methyl norleucine with hexafluoroacetic anhydride the expected 1,3-oxazolidin-5-one derivatives are formed only as by-products. As main products 3-[methyl(trifluoroacetyl)amino]-2,5-bis(trifluoromethyl)furan derivatives could be isolated, the structures of which were identified by spectroscopic methods.
    Notes: Bei der Reaktion von N-Methylhomophenylalanin und N-Methylnorleucin mit Hexafluoracetanhydrid entstehen die erwarteten 1,3-Oxazolidin-5-on-Derivate nur als Nebenprodukte. Als Hauptprodukte konnten 3-[Methyl(trifluoracetyl)amino]-2,5-bis(trifluormethyl)furan-Derivate isoliert werden, deren Konstitutionen mit spektroskopischen Methoden ermittelt wurden.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1984 (1984), S. 1672-1684 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Structure of Stenothricin - Revision of a Previous Structure AssignmentA deviation from the previously assumed molecular mass was proved by fast-atom bombardment mass-spectrometry for the peptide antibiotic stenothricin. Recent investigations of a partial hydrolyzate revealed the presence of α-ketobutyrylvaline formed by hydrolysis of an α,β-dehydroaminobutyric acid (DH-Abu) moiety. Fragments obtained by partial hydrolysis of stenothricin after catalytic hydrogenation show that the previously identified tripeptide D-aThr-L-Ser-L-Dpr is linked over DH-Abu to the tetrapeptide L-Val-D-Ser-L-Lys-Sar. The carboxy group of Sar is esterified with the hydroxy group of D-aThr. The N-terminus is formed by D-cysteic acid, which is N-acylated by β-ketoacyl residues and is connected to the cyclic octapeptide lactone via the amino group of D-a Thr.
    Notes: Die durch Fast-Atom-Bombardment-Massenspektrometrie gegenüber früheren Annahmen nachgewiesene Abweichung der Molmasse von Stenothricin erforderte eine erneute Untersuchung dieses Peptidantibiotikums. Gegenüber früheren Befunden konnte im Partialhydrolysat zusätzlich α-Ketobutyrylvalin identifiziert werden, das durch Verseifung von α,β-Dehydroaminobuttersäure (DH-Abu) entsteht. Nach katalytischer Hydrierung von Stenothricin durch Partialhydrolyse erhaltene Fragmente zeigen, daß das schon früher identifizierte Tripeptid D-aThr-L-Ser-L-Dprüber DH-Abu an das Tetrapeptid L-Val-D-Ser-L-Lys-Sar gebunden ist. Die Carboxygruppe von Sar ist außerdem mit der Hydroxygruppe von D-aThr verestert. Die durch β-Ketoacylreste N-acylierte D-Cysteinsäure bildet den N-Terminus und ist über die Aminogruppe von D-aThr mit dem Octapeptidlacton verknüpft.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Amino Acids and Peptides, III1).  -  Preparation of 1,3-Oxazolidin-5-one Derivatives from N-Methyl Amino Acids with Hexafluoroacetic AnhydrideN-Methyl amino acids react with hexafluoroacetic anhydride to give 1,3-oxazolidin-5-one derivatives in good yields. The structure of these products has been derived by 1H-NMR, mass and IR spectroscopy. Alkaline hydrolysis results in the formation of α-keto carboxylic acids. The reaction of 4-trifluoroacetylmethylene-1,3-oxazolidin-5-one derivatives with ammonia yields Δ3-pyrrolin-2-one derivatives, while methanol results in ring opening and formation of methyl esters of α,β-unsaturated N-methyl amino acids.
    Notes: N-Methylaminosäuren reagieren mit Hexafluoracetanhydrid in guten Ausbeuten zu den 1,3-Oxazolidin-5-on-Derivaten 1a - c und 3a - c, deren Struktur durch 1H-NMR-, Massen- und IR-Spektroskopie bestimmt wurde. 4-Benzyliden-3-methyl-2-trifluormethyl-1,3-oxazolidin-5-on (1b) wurde alkalisch zu Phenylbrenztraubensäure hydrolysiert. Bei der Reaktion der 4-Trifluoracetyl-methylen-1,3-oxazolidin-5-on-Derivate mit NH3 entstehen Δ3-Pyrrolin-2-on-Derivate. Mit Methanol bilden sich unter Ringöffnung die Methylester α,β-ungesättigter N-Methylaminosäuren.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metabolites of Microorganisms, 1891)  -  Structure Elucidation and Partial Synthesis of the Nucleoside Antibiotic Nikkomycin BIn the culture filtrate of Streptomyces tendae, from which the nucleoside antibiotics nikkomycin Z2) (1a) and nikkomycin X3) (1b) were isolated, a third component, nikkomycin B (7), was found. This new antibiotic contains a p-hydroxyphenyl residue instead of a 3-hydroxypyridyl residue in the amino acid moiety (6). The amino acid is linked to a 5-amino hexuronic acid to which 4-formyl-4-imidazolin-2-one is bound as an N-glycoside. The structure of the new amino acid constituent could be derived by mass spectrometry and was confirmed by synthesis of a mixture of diastereomers of 2-amino-4-hydroxy-4-(p-hydroxyphenyl)-3-methylbutyric acid.
    Notes: Das Kulturfiltrat von Streptomyces tendae, aus dem die Nucleosidantibiotika Nikkomycin Z2) (1a) und Nikkomycin X3) (1b) isoliert werden konnten, lieferte noch Nikkomycin B (7), das an-stelle des 3-Hydroxypyridin-Systems von 1 einen p-Hydroxyphenyl-Rest im Aminosäurebaustein 6 enthält. Dieser ist peptidartig mit einer 5-Aminohexuronsäure verknüpft, an die 4-Formyl-4-imidazolin-2-on N-glykosidisch gebunden ist. Die Ableitung der Konstitution des neuen Aminosäurebausteins gelang durch Massenspektrometrie und Synthese eines Diastereomerengemisches der 2-Amino-4-hydroxy-4-(p-hydroxyphenyl)-3-methylbuttersäure (6). In der biologischen Aktivität ist Nikkomycin B von den genannten Vertretern dieser Gruppe nicht zu unterscheiden.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1980 (1980), S. 1384-1391 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metabolites of Microorganisms, 1901).  -  Ketalin, a Metabolite from Streptomyces Tü 1668On testing 25 streptomyces strains for metabolites with reducing properties by a novel concept of “chemical screening” a polyfunctional compound with the elemental composition C11H20O4 was isolated from streptomyces lavendulae. On the basis of chemical and spectroscopic investigations this compound is assigned the structure of 1,3,8-trihydroxy-7-methyl-2-methylene-4-nonanone (2). The substance, which was named ketalin, is antibacterially inactive, but displays ionophoric activity in a liposome test.
    Notes: Bei der Überprüfung von 25 Streptomycetenstämmen auf Metabolite mit reduzierenden Eigenschaften in einem, seiner Konzeption nach, neuartigen, “chemischen Auswahlverfahren” (“chemisches Screening”) konnte aus Streptomyces lavendulae eine polyfunktionelle Verbindung der Summenformel C11H20O4 isoliert werden. Aufgrund von chemischen und spektroskopischen Untersuchungen wurde der Verbindung die Konstitution eines 1,3,8-Trihydroxy-7-methyl-2-methylen-4-nonanons (2) zugeordnet. Die Substanz, die Ketalin genannt wurde, ist antibakteriell inaktiv, weist aber im Liposomentest ionophore Wirkung auf.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metabolites of Microorganisms, 199.  -  Structure Elucidation of the Nikkomycins I, J, M, and NNikkomycins are nucleoside antibiotics exhibiting fungicide and insecticide activity which is due to an inhibition of chitin biosynthesis. From the culture filtrate of Streptomyces tendae the previously described nikkomycins Z2) (1 a) and X3) (1 b) have been isolated as major components. As minor components the nikkomycin B4) (1 c) as well as the nikkomycins I (1 d), J (1 e), M (1 f), and N (1 g), described in this paper, have been isolated.
    Notes: Die Nikkomycine sind Nucleosidantibiotika mit fungizider und insektizider Wirkung, die auf einer Hemmung der Chitinbiosynthese beruhen. Das Kulturfiltrat von Streptomyces tendae liefert als Hauptkomponenten die bereits beschriebenen Nikkomycine Z2 (1 a) und X3) (1 b). Als Nebenkomponenten lassen sich aus dem Kulturfiltrat die Nikkomycine B4) (1 c) sowie die im folgenden beschriebenen Nikkomycine I (1 d), J (1 e), M (1 f) und N (1 g) isolieren.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on the Configuration and Conformation of the Nucleoside Residues of the NikkomycinsThe configuration of 5′-amino-5′-deoxy-β-D-allofuranuronosyl derivatives of uracil and 4-formyl-4-imidazolin-2-one could be assigned to the C-terminal nucleoside residues 1 and 2, respectively, of the nikkomycins, according to 1H NMR spectroscopy, circular dichroism, and X-ray analysis. The latter method also showed that 1 and 2 have C-2′-endo-C-1′-exo conformation (21T) with gauche (g+) position of hte CO⊖2-group, trans (t) position of the NH⊕3-group, and anti position of the base. The conformation in solution was determined by 1H NMR spectra and from the 13C-1-H-vicinal couplings and shows only minor deviations from the conformation of the crystal.
    Notes: Den in den Nikkomycinen C-terminal gebundenen Nucleosiden 1 und 2 konnte durch 1H-NMR-Spektroskopie, Circulardichroismus und Kristallstrukturanalyse die Konfiguration von 5′-Amino-5′-desoxy-β-D-allofuranuronosyl-Derivaten des Uracils bzw. 4-Formyl 4 imidazolin-2-ons zugeordnet werden. Die Kristallstrukturanalyse zeigte darüber hinaus, daß 1 und 2 in der C-2′-endo-C-1′-exo-Konformation (21T) vorliegen, wobei die CO⊖2-Gruppe die gauche-Lage (g+), die NH⊕3-Gruppe die trans-Lage (t) und die Base anti-Stellung einnehmen. Die Konformation in Lösung wurde aus 1H-NMR-Spektren und durch Bestimmung der 13C-1H-Vicinalkopplungen ermittelt und weicht nur geringfügig von der Konformation im Kristall ab.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...